<!--
 * @Author: jay
 * @Date: 2021-08-12 19:11:10
 * @LastEditTime: 2021-08-12 19:38:48
 * @LastEditors: Please set LastEditors
 * @Description: 优先级
 * @FilePath: \Briup\Common\study\2-css\9-优先级.html
-->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>优先级</title>
    <style>
        ul.menu{

        }
        ul.menu > li.menu_item{

        }
        ul.menu > li.menu_item > ul.sub_menu{

        }
        ul.menu > li.menu_item > ul.sub_menu > li{
            color: lightcyan;
            line-height: 2em;
        }
        #introduce{
            color: lightcoral;
            background-color: lightpink;
        }
        .si{
            color: gray !important;
            border: 3px solid #ccc
        }
    </style>
        
    </style>
</head>
<body>
    <div class="tyut">
        <header>
            <div class="top_line"></div>
            <div class="second_line"></div>
                <div class="logo"></div>       
                <ul class="menu">
                    <li class="menu_item">
                        <span>人才培养</span>
                        <ul class="sub_menu">
                            <li >本科生教育</li>
                            <li >研究生教育</li>
                        </ul>
                    </li>
                    <li class="menu_item">
                        <span>学校概况</span>
                        <ul class="sub_menu">
                            <li id="introduce" class="si" style="color: blue;">学校简介</li>
                            <li >历史</li>
                        </ul>
                </ul>
        </header>
    </div>
</body>
</html>